In very simple words, when you have a group of functions that you want to be executed without disturbing and without being disturbed by other tasks in the PC, being the most notable of them serving the User Interface, you should think to a multithreaded paradigm. The thread pool is no more than a group of independent threads with some functionality added to improve internal thread handling and in general system efficiency.
You can find detailed informations on multithreading in the CVI help (see Creating Applications >> Creating Multithreaded Applications chapter that starts with Reasons for Multithreading topic).
CVI already comes with some examples of multithreading that you can list by using the Example Finder: execute Help >> Find Examples... menu function, the open the Search tab on the left and enter "Multithreading" in the search field, next double-click on the underlying results and you will be prompted with a list of examples in the middle of the window.
I suggest you to look at Simple and OnePanel examples first.
